Aircraft control



R. M. NARDONE AIRCRAFT CONTROL Aug. 1, 1945..

Origirial Fil ed' Sept. '7, 1959 INVENTOR.'

Romeo M. New

Patented Aug 7,1945

UNITED; STATES PATENT OFFICE Amcau'roonrnor. Romeo M. fiardone, Westwood, N. 1., assignorto Bendix Aviation Corporation, South Bend, Ind a corporation of Delaware Original application September 1,1939, SerinlNo. 293,818. Divided and this application December 20,1940, Serial No. 311,047 I 2 Claims. (in. I'm-13 5.6)

This invention relates to aircraft, and particularly to the control of an aircraft engineand the propeller driven thereby.

An object of the invention is to provide novel means for controlling the pitch of the propeller blades. v

As the invention is disclosed herein, the control means operates upon a propeller pitch changing mechanism of the character described in Martin PatentNo. 2,081,946, and is efiective to turn the propeller blades beyond the normal pitch range are, by reason of the development of considerably higher fluid pressure than that of which theengine driven pump of the Martin patent system would be capable (particularly if there should be a failure of engine parts); the higher pressure being in turn produced by driving a fluid compressor or pump through'independent means, as by connection thereof to the armature shaft of a high speed motor such as that commonly incorporated in engine starter mechanism, one such mechanism being illustrated in the accompanying drawing wherein:

Fig. 1 is a diagrammatic view of a system embodying the present invention; and v 2 is a transverse view along line 2-2 of In the various views the numeral liigenerally indicates a power plant of the internal combustion engine type and including a controllable pitch propeller, generally indicated at l2, having two or more radially disposed blades I4 rotatably mounted at their root or base ends in a hub'barrel member ii for pitch changing movement about their longitudinal axes. The pitch angle of the blades I4 is controlled by a pair of centrifugallygactuated counterweights l8 directly connected to the respective blades and a hydraulic mechanism 20 operatively connected to the counterweights; this being the type of pitch changing mechanism disclosed in detail in Martin, et a1. patent, above identified.

flight, with the associated engine in generatin power normally and with the pitch of the bladesvariable over the normal, limited-range.

There will next be described the auxiliary pressure fluid supplying means adapted to be brought into operation in an emergency to increase the force applied to cylinder 22 and thereby swing theblades beyond the normal range. As shown, such auxiliary means includes a second pump 28 adapted to receive oil from source 2|, as by way of supply pipe 29, and pump such oil to the cylin-' -der 22, as by way of conduit 30. This pump is -normally idle, but in an emergency can be ener-' gizedto operate to develop a pressure far in excos of the capacity oi pump P, and from a source 0! Power that is available even-though the'engine it has failed and, in consequence of such failure, is delivering no power whatever.

This source of power for operation of pump 28 is shown in Fig. 1 as involving a high speed electric motor" having an armature shaft- 33 normally coupled to flywheel 34 of an engine starter mechanism, but adapted to be drivably connected to the pump 28 through operation of coupling linkage indicated in Fig. 2 and also in Fi 1 just below the section line 2-2. The engine starter includes an engine engaging clutch member 33 and a speed reducing gear train whose high speed end is constituted'by a pinion 33 1'0- tatable with flywheel 34, and whose low speed end consists of a gear adapted to rotate a barrel 42 housing a presetclutch of the overload yielding type (such as illustrated in detail in Lansing Patent No. 1,833,948) whereby rotation is imparted to the engine engaging clutch element 36. Movement of the clutch element 36 into engagement with corresponding clutch element 31 of the engine is under the control of axially movable rod 38 passing centrally and siidably through clutch As in the Martin, et a1. patent, the counterweights tend to turn the blades M in one direction,-and the movable cylinder 22 of the-hydraulic mechanism is operative to overcome this tendency and turn the blades in the opposite direction, the hydraulic pressure for this purpose being normally produced through operation of the engine driven pump P pumping oil from the source 2l at a rate which varies according to the setting of a governor operated valve located in a housing 23 and controlling delivery of oil to-the conduit 24 leading to the cylinder 22; said valve in housing 23 being preferably identical in structure and -mode of operation to the valve 38 illustrated in Fig. 2 ofthe Martin, et al. patent.

The pressure fluidsupplying means movable into the clutch meshing manual means, if desired, or by shown) from a suitable 'the rock shaft coiled. The winding (not shown) of this meshbarrel 62 and connecting with clutch member 36 through yieldable means in the aforesaid Lansing patent or directly 'as indicated. Therod is normallyrestrained in the clutch-retract ng position shown by suitable means such as coiled torsion spring 43 corresponding spring I06 of the aforesaid Lansing patent, and 18 position by energization of a solenoid whose phmger' 5| connects with rod as by way of the intervening levers 52 and 53 and 54 about which the spring 43 1s ing solenoid may be interposed in a circuit (not source, which sourceand circuit may also include, by means of parallel connections. the windings of the electric motor 32. Y

In case of motor failure (or if the source of current is temporarily insufllcient) the starter may, be operated by accelerating the flywheel 3t manually through the instrumentality of the to the coiled torsion manually rotatable shaft 35 connecting with the starter gear train as indicated at 53 and 31.

spring 63 bears at one end against the base of 4 the socketed part of armature shaft 33, and at its opposite end exerts pressure on clutch element 66 to hold the latter in the meshed position shown. A rod 61 slidably extends through armature shaft 33 and operatively connects with clutch 38 as by means of a key 39, hereby rearward sliding of rod- 61 will draw clutch 36 to the right and interrupt driving relationship between armature shaft 33 and flywheel 33, and at the same time establish driving relationship between the said armature shaft 33 and the gear train leading to and operatively connecting with the rotor of the propeller feathering pump 23.

To bring about such rearward movement of rod 61 there is provided a bifurcated lever H straddling the rod 61 and abutting the hub of a gear 12 secured by suitable means to the rear end of said rod. where the latter protrudes beyond the bearing and retainer assembly I3 at the rearof armature shaft 33. Supports 13 provide pivotal mounting for lever II, and a rocking thereof about pivot bearing 11 is effected by reciprocation of a bar at 13. As shown in Figs. 1

and 2 this bar I8 is slidably received in the up-.

per portion 13 or the motor housing and includes 'a notch 3| having a cam edge 32 (Fig. 2) ngageable with the upper end 33 of lever ll, to rock the latter in response to a pull exerted upon the bar actuating cable 33. in the direction of the arrow in H8. 2. The gear train 33, 31, 33 is thereby coupled for rotation with the armature shaft of the motor 32 and serves to produce rotation oi the rotor of the pump 23, at a speed proportional to that of the motor 32, there being preferably some speed reduction therebetween and the gear sizes for the elements 33, 31 and 88 being so chosen as to achieve this end.

This application'is a division of my application Serial No. 293,818, filed September 7, 1939.

What I claim is:

1. In combination with an internal combustion engine driven propeller, engine starting means including a motor for imparting. initial rotary movement to said propeller, means. including a pump for feathering said propeller, means for coupling said motor to said pump to 'impart rotary movement to the latter, said 0011- pling means including a rod passing through said 2. In combination with an internal combustion engine driven propeller, engine starting means ROMEO M. NARDONE. 

